Software Reliability

During the last decade there have appeared in the literature many contributions on the reliability aspects of computer hardware, but relatively few on software. We see this balance changing as software is now becoming the most expensive and complex item in a computer installation. This situation is intensifying as applications become more sophisticated, as larger teams are required to produce the software, and as software mistakes that enter operational systems become more costly. We believe that this condition will be remedied when tools as powerful as those available for ensuring the reliability of hardware become available for software.